1. Field of the Invention
The present invention pertains to manual saws, particularly to small saws holdable in one hand. The invention particularly concerns a small hand-held saw activated by compression between the thumb and opposing fingers for both clamping and sawing or cutting materials, particularly lightweight materials such as are commonly used in crafts and hobbies.
2. Background of the Invention
Small hand-held saws are useful for cutting a variety of paper, cardboard, fabric, plastic, wood, foam and other lightweight materials. These materials are too thick or too tough to be readily severed by scissoring. Such materials are commonly used in crafts and hobbies.
A saw for craftsmens' and hobbyists' use on fairly light weight materials would preferably be light weight, relatively inexpensive, and relatively safe. It would be readily manipulatable by individuals, such as children, having only limited manual dexterity and/or strength. Despite its inexpensive construction and light weight, it would preferably be highly effective and durable in use for sawing. It would preferably be capable of readily receiving replacement saw blades. It would preferably simplify the process of cutting curves and of free form patterning.
The sawing of lightweight materials requires that the materials should be firmly held, such as in a vise, so that (i) the material is not unduly distorted by action of the sawing and (ii) the sawing may reliably proceed along a predetermined path. Materials are commonly clamped in a vise prior to commencing sawing, and are held in the vise during sawing. The positioning and clamping of a workpiece within a vise must be performed correctly. The workpiece must be aligned along the intended saw line. The workpiece must be securely held in order that the stresses induced by sawing do not cause distortion in the workpiece resulting in irregular or improper results such as a crooked saw line or nicked edge. Correct positioning and tight clamping of a workpiece in a vise prior to sawing may be especially difficult for children and other novices who have only limited planning ability, knowledge, dexterity, strength, and/or skill.
Accordingly, it is also desired, insofar as is possible, that a simple craftsmens' or hobbyists' saw for lightweight materials should also integrally incorporate a means for positioning and holding the workpiece in satisfactory alignment during the operation of sawing. This means would preferably be sufficiently simple so as to readily be operated by novices and children.
It would also be preferable if the positioning and holding could somehow be accomplished by the same forces applied from the same hand and its fingers as do otherwise accomplish the sawing. Once a workpiece was registered, inserted, or positioned to such a tool then it could be both held and sawed by the same forces.
Finally, it would be useful if the application of forces to the workpiece for holding the workpiece did not interfere with application of the same forces to the workpiece for sawing the workpiece. In particular, sawing typically involves a power stroke for cutting or slashing the workpiece and a release stroke for repositioning the saw blade for another power stroke. It is desirable that the workpiece should be pressured against the saw blade only during the power stroke, and should not be pressured against the same blade during the release stroke. Meanwhile that the forces pressuring the workpiece against the saw blade are selectively applied during the sawstrokes, it is desirable that the workpiece should be continuously securely held at least until the sawing, which normally consists of many sawstroke, is complete.
It is known to attempt the holding of a workpiece by the same tool that otherwise accomplishes sawing or cutting of the workpiece. U.S. patent Ser. No. 2,608,748 to Kirkwood for a RING SIZING TOOL shows a pliers-like sawing tool that mounts a ring workpiece during sawing. The ring workpiece is not clamped, but is abutted against a retaining lip of the tool in a position where it cannot escape a saw blade. The saw blade is forced against the ring workpiece continually during both directions of the sawstrokes.
U.S. patent Ser. No. 3,888,006 to Roberts for a CLIPPING DEVICE FOR FRUIT STEMS AND THE LIKE shows a finger operated tool that slices a fruit stem between a razor blade and an elastomeric pad. The fruit stem is not clamped, and is not subject to any more retention than simply resting on the pad except during the clipping stroke.
U.S. patent Ser. No. 4,437,237 to Ducret for a SWING SAW FOR CUTTING METAL CONDUIT shows a hand tool that clamps a workpiece conduit, and selectively clamps such conduit under hand force of the operator, for the duration of a sawing operation. A saw blade may be reciprocated under hand force of the operator while it is selectively pressured into contact with the workpiece conduit during desired portions of each sawstroke. Unfortunately, the hand force of the clamping and the hand force of the clamping and the hand force of the sawing must arise from the operator's two hands, and are not the same force arising from a one hand. The two-handed tool of Ducret thusly permits holding a workpiece conduit in a one-hand clamp while sawing the workpiece conduit with a saw registered to the workpiece with a remaining hand. The tool of the present invention, also usable to saw conduit, will be seen to accomplish the same clamping and sawing operation by use of but one hand.